Bayer Leverkusen chief Rudi Voeller admits Andre Schurrle has his heart set on moving to Chelsea.
Chelsea have failed with multiple offers for Schurrle this summer.
"André has been thinking about Chelsea - that's legitimate," said Voeller.
"Saying no was easy for us.
"It would be too soon for us to find a replacement of equal value. He and Lars Bender must stay here."